San Francisco 49ers Stadium Under Construction

That's at no extra cost to Santa Clara taxpayers, who approved an $850 million bond measure to help pay for the cost of the NFL's newest stadium. At the same time, the stadium's final bill has risen by about $336 million over the last three years, the newspaper reported.

The extra money will pay for "new tech features" that will "enhance the fan experience," according to team officials. Just what those are is "unspecified," the newspaper reported.

San Francisco 49ers Stadium Under Construction

The 49ers will began paying off the Stadium Authority, the public entity that took on the debt, with $24.5 million annual installments, the newspaper reported.

The loan, originally thought to carry a 7 percent interest rate, will now carry a 5 percent interest rate.